Fusible link



Oct 21 1924.-

1,512,117 J. J. I YTH FUSIBLE LINK Filed May' 19 1920 fnrenfar Jam? M:Z. 310 /7 Patented Got. 21, 1924.

UNITED STATES JOHN J. LYTH, OE VA'LLEYEIELD, QUEBEC, CANADA.

I FUSIBLE LINK.

Application filed May 19,

To all whom may 607106'771! Be it known that 1. JOHN J. LYTH. a subjectof the King of Great Britain. and resident of the city of Valleyfield,in the Province of Quebec and Dominion of Canada, have invented certainnew and useful Tmprovements in Fusible Links. of which the following isa full. clear, and exact description.

This invention relates to improvements in fusible links for use inconnection with fire protection sprinkler systems and the like. and theobject of the invention is to provide a link which may be easily andcheaply manufactured and which will be quick and positive in operation.

The invention resides briefly in providing a pair of plates each havingan abutment or seat thereon and a rocker located between the seats andholding the plates against rela tive movement in a predetermineddirection.

In the drawings which illustrate the invention;

Fig. 1 is a plan view of a link according to this invention.

Fig. 2 is a side elevation of the link.

Figs. 3, 4; and 5 are plan views illustrating slight modifications ofthe link shown in'Fig ure 1.

Referring more particularly to the drawings, 11 and 12 designate a pairof plates. which for convenience may be referred to as back and frontplates respectively. These plates overlap and are each provided at oneend with an aperture 13 for connection with a sprinkler head or otherapparatus. The back plate 11 is bent rearwardly at a trans verse linetoward the end remote from the aperture 18, thus forming a slopingportion 14 and is then bent forwardly at substantially right angles tothe part 14 to form a transverse seat 15 located in rear of the plate12. It will be observed that the seat 15 is on the front surface of theback plate 11. The front surface of the plate 12 is provided with abent-up portion 16 forming a seat at the front of the plate. A strut.rocker or key 17 is rockably mounted on the seat 16 and passes to theback of the plate 12 and bears against the seat 15 of the plate 11. Whenthe link is loaded in the predetermined direction the plates 11 and 12tend to slide past one another. This sliding movement is resisted by thestrut or key 17 which is in compression between the plate seats butowing to the 1920. Serial No. 382,531.

inclination given the key by reason of its passage from the front to theback of the plate 12, it will rock on its seats when the link releasesunder tension and force the plates apart laterally. In making up thelinks the plates and the strut or key are connected together by solderfusible at a low temperature in the well known manner, with the resultthat the parts are held against movement at ordinary temperatures butwill, upon softening of the solder at increased temperature, move asabove discribed.

In the form shown in Figure 1 the plate 12 is, as a whole, narrower thanthe plate 11 and the strut 17 is a U-shaped wire lying at its central orroot portion scross' the plate 12. The arms of this strut pass one oneach side of the plate into engagement with the seat of the back plate11. The inclination given the portion 14 of the back plate is for thepurpose of accommodating the inclined strut as will be clearly seen inFigure 2. The seat 16, which is turned-up from the plate 12, may beformed in a variety of ways of which one is shown in Figures 1 and 2.The lower por tion of the plate 12 is made of substantially the samewidth as the plate 11 and. therefore projects beyond the edges in theremainder of the plate length. These projections are turned upwardly toform a seat for the strut. It will be noted that. as only the thicknessof the plate is presented as a seat. there are two Inns in order toprovide stable support for the strut. While these lungs have beenformed. by turning metal at the edefes upwardly or toward the centreline of the plate, it will be understood that the same result may beproduced by starting on a cut in the centre line of the plate andturninp; the metal upwardly and away from the centre as shown in Figure5. It will also be understood that a seat may be provided by turning upa sinsrle tongue of'metal in the transverse direction of the plate asshown in Figures 3 and 4. Apart from the method of p oducing; the seat16 the forms shown in Figures 3 and differ from the form shown in Figure1 in the provision for the passage of the strut from the front to theback of the front plate. In Figure 1 the strut passes outside the. edgesof the plate 12. In Figure 3 the strut is of the same U-shape butnarrower and slots 18 are provided close to the edges of the plate 12.for the passage of these arms. In Figure 4 a single slot 18 is prosvided in the centre line of the plate 12* and the strut, while still ofU -shape, is closed-up to pass through a' single slot. In order toprevent rocking of the narrower strut its extremities are turnedoutwardly as shown at 19 and may rest upon the seat 16 or upon the seat15 as may be found most expedient. Obviously the strut 17 shown inFigure l may be used in the inverted position shown in connection withseats 16 formed as in Figures 1 or 5. In all forms the back platellisthesame, Having thus described my invention, what I claim is 1 p r5 1. A fusible link comprising a pair of plates in slidable engagement,said plates having seats on the front faces thereof, and a strut incompression between said seats.

2. In a fusible link, a pair of plates in slid able engagement, seats onthefront faces of said plates, and a strut in compression between said.seats extending through the thickness of oneof the plates.

v 3 A fusible linkcomprising a pair of' plates in slidable engagement, aseat on the front surface of each plate, and a U-shaped strut incompression between said seats.

H 4:, A fusible link comprising a pair of plates in slidable engagement,one of said plates being turned away from the other plate and thensharply toward the other plate' to form aseat on the front face thereof,a lug on the front face of the other plate forming a second seat, and alink in com- .6. A fusible link comprising a pair of plates in slidableengagement and each aper-- tured toward one end, a seat forming lugsturned up on the front surfaces of the plates toward the ends thereofremote from the apertures and a strut in compression between said lugs.

7. A fusible link comprising a pair of plates in slidable engagement,seats projecting from corresponding surfaces of said plates, one of theplates being formed for the passage of a link from front to backthereof, and a strut in the seats passing from front to back ofsaidplate.

8. A fusible link comprising a front. plate and a backplafte, the frontpl'atebeing'cut away to expose part of the-back plate and to givepassage to a strut, seats formed on the front surfaces of the plates andstrut held in compression between said seats.

In witness whereof, I have hereunto set my hand.

JOHN J. LYTH.

compression between-

